RecN SOS gene and induced precise excision of Tn10 in Escherichia coli.

A mutant defective in the induced excision of Tn10 was isolated by decreased papillation on MacConkey-galactose plates with mitomycin C. The mutation involved was characterized as recN by genetic mapping and complementation. This mutant, as well as a previously characterized recN mutant (recN262), showed a markedly decreased frequency of excision of Tn10 after treatment with UV or mitomycin C. These observations indicate that recN is involved in the induced excision of Tn10.